Modern versions of Chrome, Firefox, and Edge do not work on Vista. You will likely need to use a browser like Mypal or a legacy version of Firefox to access the web. Better Alternatives
The most reliable source for "abandonware" or vintage software is the Internet Archive. Users frequently upload original disk images (ISOs) of Windows Vista Business. These are typically "clean" rips of the original retail or OEM DVDs.
Are you planning to install this on or a virtual machine ?
Look for hashes matching the official MSDN releases.
If your goal is simply to run an old app, consider using on Windows 10 or 11 first. Alternatively, setting up a Virtual Machine using VirtualBox or VMware is much safer than installing Vista as your primary operating system on physical hardware.
Downloading operating systems from third-party sites carries security risks. To ensure the file hasn't been tampered with, you should verify the SHA-1 or MD5 hash of the ISO file against known original Microsoft values.